Answer:
An element is a pure substance and is made of only one type of atom; it cannot be broken down into a simpler substance. Overview: In this activity, students practice using the periodic table to look up chemical symbols of elements and use paper circles to construct and compare models of elements and compounds.
Explanation:
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Answer:
The formula of the original halide is SrCl₂.
Explanation:
- The balanced equation of this reaction is:
SrX₂ + H₂SO₄ → SrSO₄ + 2 HX, where X is the halide.
- From the equation stichiometry, 1.0 mole of strontium halide will result in 1.0 mole of SrSO₄.
- The number of moles of SrSO₄ <em>(n = mass/molar mass) </em>= (0.755 g) / (183.68 g/mole) = 4.11 x 10⁻³ mole.
- The number of moles of SrX are 4.11 x 10⁻³ moles from the stichiometry of the balanced equation.
- n = mass / molar mass, n = 4.11 x 10⁻³ moles and mass = 0.652 g.
- The molar mass of SrX₂ = mass / n = (0.652) / (4.11 x 10⁻³ moles) = 158.62 g/mole.
- The molar mass of SrX₂ (158.62 g/mole) = Atomic mass of Sr (87.62 g/mole) + (2 x Atomic mass of halide X).
- The atomic mass of halide X = (158.62 g/mole) - (87.62 g/mole) / 2 = 71 / 2 g/mole = 35.5 g/mole.
- This is the atomic mass of Cl.
- <em>So, the formula of the original halide is SrCl₂</em>.
The correct answer is Ca(CIO3)2 i believe
The correct option is ARGON.
To quickly find out the element that is been described by the electronic configuration, write down and add together all the index figures in the electronic configuration. The index figures in the above electronic configuration are 2, 2, 6, 2 and 6. If you add all these figures together, you will get 18 and the element that has the atomic number of 18 is argon.
Answer: The reactants
Explanation: These are the substances that go into a chemical reaction and start it.